BISTABLE MAGNETIC ACTUATOR

摘要

PCT No. PCT/GB94/01975 Sec. 371 Date Mar. 7, 1996 Sec. 102(e) Date Mar. 7, 1996 PCT Filed Sep. 12, 1994 PCT Pub. No. WO95/07542 PCT Pub. Date Mar. 16, 1995A magnetic actuator (10) suitable for the operation of electric circuit breakers which uses a laminated yoke structure (12) to increase permanent magnet flux holding forces. The actuator comprises a magnetic yoke (12) which forms both low and high reluctance flux paths with at least one permanent magnet (30) and an armature (40) axially reciprocable in a first direction within the yoke (12). The actuator is configured to provide a first low reluctance flux path and a first high reluctance flux path when the armature (40) is in a first position and a second low reluctance flux path and a second high reluctance flux path when the armature (40) is in a second position. A pair of electromagnetic coils (60, 61) are used to drive the armature (40) between the first and second positions. The geometric design of the actuator is such that by increasing one linear dimension of the device by adding lamination to the yoke and making corresponding increases in the same linear dimension of magnet and armature the permanent magnet flux can be increased to meet any specification of device required using the same basic components. The design of the laminated yoke is adapted to considerably improve the low reluctance path to form a more compact device and provide higher holding forces and faster switching times.